12v battery...that old chestnut!

[Roker]

On 4/29/2024 at 8:47 PM, Dylanfan said:

I think I’d be straight back to the main dealer, there must be something draining the battery! As I said above, never had a problem & now at over 4 years old.

I have noticed that most people on here with this problem have cars that are not very old, strange!!

 When not in use there is a small current taken from the 12v Battery to do the utilities like computer memory, dash cam etc. a Battery doesn't suddenly stop working it deteriorates and gradually run below the starting volts so that the time it can stand without starting will become shorter progressively 

[Paul 85]

My Corolla TS 2.0 Excel was handed over on 4th April. My first long run was on 13th, 155 miles after which, I parked, turned on the radio and after less than 5 minutes a 'Low Battery - turn power off' message appeared. That was the second time the 'Low battery' message had been displayed. I have notified the dealer who is "looking into it and will get back to me." I'm waiting.

No further Battery warnings, however, and everything seems to be working. It does seem strange to me that the media can only be played with the power button switched on. This is my first hybrid so I guess I have much to learn.

[Corolly Poly]

15 minutes ago, Paul 85 said:

My Corolla TS 2.0 Excel was handed over on 4th April. My first long run was on 13th, 155 miles after which, I parked, turned on the radio and after less than 5 minutes a 'Low battery - turn power off' message appeared. That was the second time the 'Low battery' message had been displayed. I have notified the dealer who is "looking into it and will get back to me." I'm waiting.

No further battery warnings, however, and everything seems to be working. It does seem strange to me that the media can only be played with the power button switched on. This is my first hybrid so I guess I have much to learn.

are you turning the hybrid system on or just accessories? Turning a key to accessory in conventional vehicles is normally required to turn the radio on etc.

[AndrueC]

Some interesting comments here and from reading other forums it appears that Toyota have implemented some form of warning. Or at least that the car starts playing up when the Battery is getting low.

Whichever it is that seems like it offers some relief. I had this vision of going out to my car one day it was just dead. But it seems like that won't happen. There will be at least some indication in the days or weeks leading up to it.

That being the case I'm happy to wait. It appears that a new Battery costs over a hundred quid - closer to two hundred if you want it fitted so as long I'm not suddenly going to be caught out I'll leave it be.

[TonyHSD]

37 minutes ago, AndrueC said:

Some interesting comments here and from reading other forums it appears that Toyota have implemented some form of warning. Or at least that the car starts playing up when the battery is getting low.

Whichever it is that seems like it offers some relief. I had this vision of going out to my car one day it was just dead. But it seems like that won't happen. There will be at least some indication in the days or weeks leading up to it.

That being the case I'm happy to wait. It appears that a new battery costs over a hundred quid - closer to two hundred if you want it fitted so as long I'm not suddenly going to be caught out I'll leave it be.

That’s right , these aren’t cheap and before its completely dead there is no point really to get it replaced just in case as preventative measure. Booster pack or smart charger are better investment as addition to the car garage accessories. 
I waited till the very last moment and now facing some trouble finds a Battery but that’s because car trade and car parts business has always been unreliable, so it is what it is. 
 

[Roy124]

2 hours ago, Paul 85 said:

My Corolla TS 2.0 Excel was handed over on 4th April. My first long run was on 13th, 155 miles after which, I parked, turned on the radio and after less than 5 minutes a 'Low battery - turn power off' message appeared. That was the second time the 'Low battery' message had been displayed. I have notified the dealer who is "looking into it and will get back to me." I'm waiting.

No further battery warnings, however, and everything seems to be working. It does seem strange to me that the media can only be played with the power button switched on. This is my first hybrid so I guess I have much to learn.

Paul, it is working exactly as they all do.  My Mercedes with a stop/start specification Battery twice the physical size of the Toyota's would automatically switch off the radio when running in accessory mode after a few minutes

IIRC my earlier cars had no accessory mode.  Ignition  had to be on to power the radio; in that state the coil was live as was the radio and we anticipated the radio would flaten the Battery.

Your low Battery warning is simply a warning and not suggestive of a massive voltage drop.

 

[TonyHSD]

I believe our cars has 3 separate warnings about battery: 

1. Auto switch off - warning will appear on dashboard about the car is about to turn off to preserve the 12v battery 

2. Low Battery power - this is when your 12v Battery has reached low voltage. 
3. Low key Battery - your remote key battery is getting low

These are three warnings I personally experienced in my Auris hybrid. 

[SDR]

I am a new owner of a (new) Corolla TS 1.8.   I did my homework before ordering and am wary of 12v Battery issues which, as mentioned above, seem to plague newer examples.   Possibly, as also mentioned above, because of the DCM/Connected Services, alarm and maybe keyless entry hunting for a key.   I also researched the new Yaris which is arguably worse.

So first night in my ownership it went on the smart charger which was showing green by the morning.   I haven't had any warnings or issues but the car is in fairly regular use.   I have not used ACC or ON mode (made sure to keep in READY mode whilst going through laborious setting up of meter and central screens).

I also carry a small Li-ion jump pack in the car.   Thankfully, much smaller and lighter than the lead-acid jump packs of old.

A word about Battery types.   My car is a 1.8 so the 12v Battery is under the bonnet (it's a standard flooded type as far as I can tell).   The 2.0 models have the 12v battery in the boot, which is classed as part of the passenger compartment.    From what I have read, this is actually AGM for safety reasons.   The 12v battery in the  new Yaris, which is located under the back seat, is apparently also AGM for the same reasons.  I don't know, I don't work for Toyota, it's just what I have read;   but it makes sense to me because of the risk of the battery being damaged and spilling sulphuric acid over people in a bad accident.   It is nasty stuff. 

As far as replacing an AGM battery with a standard flooded type is concerned, or vice-versa, personally, I wouldn't;   and not just for safety reasons.    I am not an expert on battery charging (I have an electronics degree but it's 1975 vintage!) but I believe that AGM batteries have a different charging regime/profile to the standard type.   For starters, I know that my smart charger bulk charges at 14.4v on the standard setting and at 14.7v on the AGM setting. 

For my own car, I would assume that the charging electronics are set for the type battery that is fitted, and probably aren't smart enough to detect a different battery type.   Unless anyone knows differently...    So I will replace like with like. 

[Roy124]

8 minutes ago, SDR said:

The 12v battery in the  new Yaris, which is located under the back seat, is apparently also AGM for the same reasons.  I don't know, I don't work for Toyota, it's just what I have read; 

This was stated or assumed but more recently the Yaris Cross Battery has been identified as a Calcium Acid Battery.  The CA is apparently a lead acid Battery with a calcium coating,which holds a charge better.

[CPN]

...and the Battery in the new 2024 Yaris is the same as the older models...

[SDR]

Interesting.   What I read was obviously wrong!   I don't think that I would be too happy about sitting in front of a plastic container of sulphuric acid, if what I read about it being mounted under the back seat is actually true.   Still, the cars have obviously passed all the type approval safety tests so maybe concerns unfounded.  

I am slightly bemused by the photo of the Battery and sticker.   It's maintenance free yet there are access plugs to the cells.   Never seen that before... but I've never owned a Japanese car before either.

[CPN]

7 minutes ago, SDR said:

Interesting.   What I read was obviously wrong!   I don't think that I would be too happy about sitting in front of a plastic container of sulphuric acid, if what I read about it being mounted under the back seat is actually true.   Still, the cars have obviously passed all the type approval safety tests so maybe concerns unfounded.

Indeed and don't forget that it is properly vented and the HV Battery fan at the other end of the seat keeps it all well ventilated.

7 minutes ago, SDR said:

I am slightly bemused by the photo of the battery and sticker.   It's maintenance free yet there are access plugs to the cells.   Never seen that before... but I've never owned a Japanese car before either.

They may look as if they are "access" plugs but I think they are only for the initial filling and can't easily be turned (I've tried) to get them out now...

[SDR]

It wasn't the gassing aspect that I was thinking about, especially as calcium batteries are apparently better than standard lead-acid batteries in this respect.   I was thinking about what might happen if hit hard - like really hard - from behind.   Still, we all have the HV Battery under the rear seat so we might get fried before being burned by acid.   I need to buy one of those 'positive thinking' books.

AFAIK, all wet batteries have the plugs (for filling).   They are just covered over with a sticker on MF types;   the Battery on my Corolla is like this, I can feel the outline of the plugs under the sticker.   I was just surprised to see the plugs left visible, as if encouraging opening/checking.

[SDR]

Getting back on topic, i.e. Battery drain, I wonder if anyone else disables their smart keys?   I do this as a routine every time I return home (the car is in regular use but not every day as I am retired).   It only takes a few seconds.

My original reason for doing so was to prevent relay theft as, once 'switched off', the key does not communicate from the car.   However, I am am sure that I have read somewhere that it not only saves drain on the key Battery but also on the 12v car Battery.   As far as the car battery is concerned, it may depend upon how close the key is to the car (in my case, it's only a few feet).

I can't remember exactly where I read that, it might have been in the user guide (which I keep in the car), the on-line guide or in the manual.   So much bed-time reading with a Toyota...

[ThomasL]

It's a good idea to switch off the "keyless key" when washing the car, otherwise water touching the door handle sensors can keep locking and unlocking the doors and drain your 12V Battery that way!

(Or move the key out of range)

This is called out in the comprehensive manual too 😁

[CPN]

2 hours ago, SDR said:

Getting back on topic, i.e. battery drain, I wonder if anyone else disables their smart keys?   I do this as a routine every time I return home (the car is in regular use but not every day as I am retired).   It only takes a few seconds.

Snap!! I do it all the time too.

2 hours ago, SDR said:

My original reason for doing so was to prevent relay theft as, once 'switched off', the key does not communicate from the car.   However, I am am sure that I have read somewhere that it not only saves drain on the key battery but also on the 12v car battery.   As far as the car battery is concerned, it may depend upon how close the key is to the car (in my case, it's only a few feet).

From what I have read, I believe you are right. (since the system stops looking for the key after a short while)

2 hours ago, SDR said:

I can't remember exactly where I read that, it might have been in the user guide (which I keep in the car), the on-line guide or in the manual.   So much bed-time reading with a Toyota...

🤣🤣

[Derek.w]

Car Battery fitted under rear bench seat are Twin lids so deemed to be rollproof , vented via a 5mm tube to the outside.

Some are manufactured without the top up plugs.